The present invention relates to processes for removal of trihalocarbons from water. More specifically, the invention relates to a process for removing compounds such as trichloroethane, trichloroethylene, and dichlorobromomethane from groundwater and to a novel adsorbent and apparatus for carrying out the process.
In the prior art, activated carbon has been used as an adsorbent to remove trihalocarbons from water. Although activated carbon is an effective adsorbent, the adsorption process is difficult to employ on a commercial scale because attempts to regenerate the adsorption bed with steam result in incomplete destruction of the trihalocarbon. Although hot air can be used to oxidize the adsorbed compounds, the hot air also reacts with activated carbon to destroy the bed. Because activated carbon is so difficult to regenerate, it is generally disposed of as waste material after being used.
A principal object of the present invention is to provide a process for adsorbing trihalocarbons from water onto particles contained in an adsorption bed, wherein the adsorbent can be regenerated with air or steam at an elevated temperature to chemically degrade the trihalocarbon without destroying the bed.
A related object of the present invention is to provide a process for preventing release to the atmosphere of gaseous HCl produced during regeneration of the adsorption bed.
A further object of the invention is to provide a novel composite adsorbent and a novel apparatus for carrying out the adsorption process of the invention.
Additional objects and advantages of the present invention will become apparent to persons skilled in the art from the following detailed description.